Audio DAC (digital-to-analog conversion) technology has improved at a steady pace over the past three decades. Broadband dynamic range performance (i.e., the difference between a noise amplitude and a maximum level) has improved at an average pace of roughly 0.7 dB per year over the last 30 years, or a one-bit performance improvement roughly every 8 years since the 1980s. The present invention significantly improves DAC dynamic range performance. To achieve this significant performance improvement, according to the present invention a number of novel design techniques can be combined and optimized, including DSP-controlled multi-path parallel D-A conversion, ADC multi-path monitor and DSP compensation and DSP-controlled noise management. Furthermore, according to the present invention ADC (analog-to-digital conversion) is used for measuring path levels in consort with DSP calibration of said path levels in a multi-path DAC topology. Furthermore, according to the present invention, multiple pre-adapted digital input signals may be processed according to alternative embodiments of the present invention. Furthermore, according to the present invention, multiple pre-adapted analog output signals may be realized according to alternative embodiments of the present invention.
Therefore, it is an object of the present invention to provide method and apparatus for digital-to-analog conversion having low noise and high maximum level.
More particularly, it is an object of the present invention to provide method and apparatus for digital-to-analog conversion having low noise and high maximum level utilizing circuitry that separately processes a most significant bits portion and a least significant bits portion of an input digital signal, particularly where noise in the analog output signal is reduced or eliminated from the high-path circuitry when the input signal has a sufficiently low level, and outputs from the low- and high-path circuitry are summed.
It is another object of the present invention to provide method and apparatus for digital-to-analog conversion which utilizes circuit behavior monitoring and feedback to improve performance characteristics.
Additional objects and advantages of the invention will be set forth in the description which follows, and will be apparent from the description or may be learned from the practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the claims.